This invention is generally directed to toner and developer compositions, and more specifically the present invention is directed to toner compositions, including magnetic, single component, and colored toner compositions with certain polymeric alcohol waxes. In one embodiment of the present invention, the toner compositions are comprised of resin particles, pigment particles, and waxes with hydroxyl functionality. There is also provided in accordance with the present invention positively charged toner compositions comprised of resin particles, pigment particles, waxes with hydroxyl functionality, and charge enhancing additives. Furthermore, there is provided in accordance with the present invention toner compositions wherein the polymeric alcohol waxes are present therein as external or internal additives. In addition, the present invention is directed to developer compositions comprised of the aforementioned toners, and carrier particles. Furthermore, in another embodiment of the present invention there are provided single component toner compositions comprised of resin particles, magnetic components such as magnetites, and waxes with hydroxyl functionality. The toner and developer compositions of the present invention are useful in electrostatographic imaging systems, especially those systems wherein blade cleaning of the photoconductive member is accomplished. Moreover, the toner and developer compositions of the present invention enable the photoconductive imaging member present in an imaging apparatus to function for extended time periods, for example, up to 100,000 cycles while simultaneously preventing the localized accumulation of undesirable toner debris thereon which can encompass sufficient areas of the photoconductive members to permit unwanted toner spots to be present on the final developed output copy. Further, the developer compositions of the present invention possess stable electrical properties for extended time periods, and with these compositions, for example, there is no substantial change in the triboelectrical charging values, and substantially no degradation in A.sub.t which is the product of the toner concentration +1 multiplied by the triboelectric charging value. Therefore, the units of measurement (.mu.c percent/grams) for A.sub.t are.+-.microcoulombs of charge on the toner particles multiplied by the percent toner concentration divided by grams of the toner particles that are separated from the developer composition by, for example, known blowing processes, which units are dependent on a number of factors inclusive of the composition of the carrier particles selected. Accordingly, thus the A.sub.t for the developer compositions of the present invention remains at, for example, from about 60 to about 80 for 300,000 developed images or copies while simultaneously maintaining high copy quality for each of the aforementioned images. Accordingly, there is permitted with the compositions of the present invention a prolonged charge exchange capability thereby contributing to a more stable development system requiring less complex control systems, and reduced maintenance of the imaging apparatus within which the compositions are incorporated. In addition, the aforementioned compositions provide for an increase in the latitudes over which a blade cleaning system can operate thereby enabling a more reliable and simpler apparatus.
By increased latitude, it is intended to refer to the achievement of obtaining an increase in the range of the load or force applied to the blade between a lower value wherein cleaning will fail, and an upper value wherein the blade undesirably bends causing the tip thereof to remain out of contact with the imaging member. Moreover, with increased latitude there can be selected a broader range of imaging member cleaning blade thicknesses, and various blade orientations with respect to the imaging member.
Developer and toner compositions with certain waxes therein are known. For example, there are disclosed in U.K. Patent Publication No. 1,442,835 toner compositions containing resin particles, and polyalkylene compounds, such as polyethylene and polypropylene of a molecular weight of from about 1,500 to 6,000, reference page 3, lines 97 to 119, which compositions prevent toner offsetting in electrostatic imaging processes. Additionally, the '835 publication discloses the addition of paraffin waxes together with, or without a metal salt of a fatty acid, reference page 2, lines 55 to 58. In addition, many patents disclose the use of metal salts of fatty acids for incorporation into toner compositions, such as U.S. Pat. No. 3,655,374. Also, it is known that the aforementioned toner compositions with metal salts of fatty acids can be selected for electrostatic imaging methods wherein blade cleaning of the photoreceptor is accomplished, reference Palmeriti et al. U.S. Pat. No. 3,635,704, issued January 18, 1972, the disclosure of which is totally incoporated herein by reference. Additionally, there are illustrated in U.S. Pat. No. 3,983,045 three component developer compositions comprising toner particles, a friction reducing material, and a finely divided nonsmearable abrasive material, reference column 4, beginning at line 31. Examples of friction reducing materials include saturated or unsaturated, substituted or unsubstituted, fatty acids preferably of from 8 to 35 carbon atoms, or metal salts of such fatty acids; fatty alcohols corresponding to said acids; mono and polyhydric alcohol esters of said acids and corresponding amides; polyethylene glycols and methoxypolyethylene glycols; terephthalic acids; and the like, reference column 7, lines 13 to 43. There is no teaching, however, in any of these patents with respect to the toner compositions with the specific polymeric hydroxy waxes selected for the invention of the present application; and moreover, the toner and developer compositions of the '045 patent do not possess many of the advantages as illustrated herein with respect to the toner and developer compositions with the polymeric alcohol waxes therein, that is for example developer compositions of the '045 patent do not possess stable electrical properties in several imaging apparatuses, and with these compositions there is degradation in A.sub.t with extended imaging impressions, that is exceeding for example 100,000 developed images; nor, for example, does the incorporation of metal salts or metal salts of fatty acids such as zinc stearate; the addition of colloidal silicas, or mixtures thereof enable the elimination of toner spots on the final image copy with positively charged toner compositions, a disadvantage alleviated with the toner and developer compositions of the present application. Moreover, the polymeric alcohol waxes selected for the compositions of the present invention were not available prior to the issuance of the '045 patent, that is September 28, 1976.
Described in U.S. Pat. No. 4,367,275 are methods of preventing offsetting of electrostatic images of the toner composition to the fuser roll, which toner subsequently offsets to supporting substrates such as papers wherein there is selected toner compositions containing specific external lubricants including various waxes, see column 5, lines 32 to 45, which waxes are substantially different in their properties and characteristics than the polymeric alcohol waxes selected for the toner and developer compositions of the present invention; and moreover, the toner compositions of the present invention with the aforementioned polymeric alcohol additives posses advantages such as elimination of toner spotting not achievable with the toner and developer compositions of the '275 patent. In addition, the polymeric additives of the present invention were not known as of the issued date of the '275 patent, namely January 4, 1983.
Other references of interest which disclose the use of amides as toner additives include U.S. Pat. Nos. 4,072,521; 4,073,649; and 4,076,641. Furthermore, references of background interest are U.S. Pat. Nos. 3,165,420; 3,236,776; 4,145,300; 4,271,249; 4,556,624; 4,557,991; and 4,604,338.
Moreover, toner and developer compositions containing charge enhancing additives, especially additives which impart a positive charge to the toner resin, are well know. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of certain quaternary ammonium salts as charge control agents for electrostatic toner compositions. There is also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. According to the disclosure of this patent, the development of images on negatively charged surfaces is accomplished by applying a developer composition having a positively charged triboelectric relationship with respect to the colloidal silica. Further, there is illustrated in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer and toner compositions having incorporated therein as charge enhancing additives organic sulfate and sulfonate compositions; and in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions containing resin particles and pigment particles, and as a charge enhancing additive alkyl pyridinium compounds, inclusive of cetyl pyridinium chloride.
Other prior art disclosing positively charged toner compositions with charge enhancing additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014; and 4,394,430. Although the above described toner and developer compositions are useful for their intended purposes, there is a need for improved compositions. More specifically, there is a need for toner compositions, including single component compositions which possess advantages not achievable with the prior art compositions. There is also a need for toner compositions with certain waxes that are particularly useful in electrostatic imaging processes wherein blade cleaning is utilized for the removal of unwanted toner particles from the photoreceptor surface; and wherein there results no undesirable toner spots on the images resulting. In addition, there is a need for toner and developer compositions that maintain their triboelectrical characteristics for extended time periods, exceeding for example 100,000 developed images. In addition, there is a need for toner and developer compositions that simultaneously enable increased blade cleaning; eliminate toner spots; maintain stable electrical characteristics for extended time periods. Furthermore, there is a need for single component toners, and colored toners that possess many of the aforementioned characteristics. Also, there is a need for toner and developer compositions with certain toxicologically safe and economical waxes therein that allow the aforementioned advantages, and other advantages to be obtained.